1,3,6-thiadiazepine-2-thiones and their production



Patented July 4, 1950 UNITED STATES PATENT OFFICE .13 6rTEIADIAZE AND TEI P DUC'JZIO James A. Shotton, Cedar Rapids, Iowa, assignor to TheFirestone Tire & Rubber iLGompany, Akron, Q hi a-corporation of Ohio NoDrawing. Applicat e e at, we.

" Serial No. 84, {196 :8 Claims.

This invention relates to the reaction or car- 'bon disulfide and1,3:substituted imidazolidines. The invention relates'to-the process ofpreparing these compounds and to the compounds themselves, which areuseful .asaccelerators and our.- ing agents for the treatment of rubberymaterials and may be useful as fungicides, insectih a b d s lfi :t rodue omp und which are believed to .be cyclic and probably are .6-d b te hxehyd iediaz iiiez-thiones. The 4 and fi positions may besubstituted,although the preferred compoundsof; this inve o e unsubst uted inthet 9ositi The following equations indicate the probable course of thereaction using formaldehyde:

R.NH.CHzCHz.NH.R.+ omo R.N.CH2OH2.N.R

i het unsa ura ed .-.a fph t,it re eh e hei alipha -,h n h hain al haic; eye1oa1 .ph e yc -sub t tute liph c. ,terp he er ey li and h d ocaron-subs tuted h ter e substi lieiite- The ..3-.. i ub$tit. t d im daziitiine wer i r a edb sl wl ad ing torm- (aldehyde (3.535 104!)perecentForrnalin) in i0 -v per cent mela exe eh e p op i -e hy enediamiev.A h g ex th m reeetieii nsued and the addition .o f fformalinwasregulated to keep the .te nperaturebelow 50 C. When diethyl,diisopropyl and -dicyclohexy1ethy1ene diamines were used, formation ofthe diamine hydrate on addition of Formalin caused solidification of thereaction mixture. On further additio .Q Fe ma hema e fied- ,A 'thpletion of most of the reactions two liquid phases (water andimidazolidine) were present. Separation wofthe diethvLQiallfl. and i ieeree i azolidine was induced by alting. Solidproducts were recrystallizedfrom benzene, .and liquids wer purified by d t l o The .NiN'etiieubtituted ethylene diamines may be symmetrical or unsymmet cal, and ma vinludev as eiibs i ie me h e yl. .prop n butyL s e .-'b .t l., tertbut lan em l, he Lhe t L o yL' d e L eetad c etc. eyelenent l, cyc e eis iethylew .e e exv ,b yl ,fu iiryl thienyl. p ri riy te y KiXQliYL t renyl boriiyl, ta etc- 1,3--dicyclohemylimidaeolidine vand its carbondieuli de teaeti n emd e -'1 ,3 -dicyclohexylimidazolidine was preparedby adding slightly more than one-half mole of '37 -per cent;formaldehyde solution to one-half-mole of -N;N'-dicyclohexylethylenediamine and allowingthe mixture-tostand over night.The mixturewas treated with potassium carbonate (anhydrous), aiter whichthe top layer was separated and distilled under reducedpressure. Themain portion of the imidazolidine came over at 173-175--C, -at 8-to10-mm.

One-half mole of the imid azolidine was reacted with-one-half -rnoleofcarbon disulflde by -;d ;i s solvingqbgth reactants in cc. of ether,"heatin to reflux tempe ature and th a l ine-t t tand ever ni ht h pteeu e de a a elle ee i l- Thee iide pred c ysta ed eneeirem acetone .1 a ml in P9111 tub thi ea t on .preduetsieeem oeed a 10 The carbon disulfidereaction carried out by rei nein .eltehe wee'n e e e ulb ee iee th eeete r c ecom os at h flux n temperature.

EXAMPLEII 1,3-diisopropylimidaeolidine and its carbon disulfide reqetionproduct ee i h xeeee ove e eeiiler ri ep tiene e NH:di e r p le h leneiami an 3' er cen periods.

formaldehyde solution were mixed. The mixture was allowed to stand-overnight. The mixture was then saturated with potassium carbonate, and theupper layer then separated and distilled at atmospheric pressure. theresulting 1,3-diisopropylimidazolidine was 183-185 C.

The 1,3-diisopropylimidazolidine was reacted with an excess of carbondisulfide in ether solution by allowing the mixture to stand overnightat room temperature. The next morning a yellow solid product had formed.In. a melting point.

tube, this product decomposed at 99 to 100C.

Various of the carbon disulfide reaction products were similarlyprepared. On analysis for sulfur (semi-micro Parr bomb) and nitrogen(micro Friedrich-Kjel'dahl) it was found that the carbon disulfide andi'inidaaolidines had re acted in molecular proportions. Information onthe reactions and reaction products is tabulated The boiling pointpfq 20below, the products being identified briefiy by giving theirN,N'-substitueiits.

Carbon disulfide reaction products Analyses Reaction Percent M. P., O.Calculated Found Substltums Solvent Yield (Corrected) I '7 PercentPercent Percent Percent N s N s Ethan u" at 6814-09. 4 1s. 72 31. 4013.82 31. 52 AlcOhOL 82 103. 12. 07 27. 58 12. O 27. Ether 61 61. 4-61.8 10. 78 24. 59 10. 75 24. 55 AlcohoL Y 97 98-99. 4 8.97 20. 51 a 95 29.2o

The. carbon disulfide reaction products of this invention areacceleratorsof the'sulfur-vulcam' ample, 1,3-butadiene,isoprene,2-cyanobutadiene- 1,3, 2 -chlorobutadien e- 1, 3,Jcyclopentadiene, piperylene, dimethyIbutadiene- IB,Z-methylpentadime-1,3, 2-vinyl-5-ethylpyridine', 2-ethy1-5-vinylpyridine, etc. Thevinyl monomers include,- for example,styrene;alpha-methylstyrene, nuclear substituted styrenes,monochlorostyrene dichlorostyrene, vinylnaphthalene; vinylbiphenyl,vinylcarbazole, acrylonitrile, methacrylonitrile,

ethacrylonitrile, chloro-acrylonitrile, acrylic acid esters containingone-to flve or :more carbon atoms in the ester group;-acrylamide, etc.As i1- lustrative of the use of these compounds asaccelerators, there isincludedhereinxresults of tests in a cured GR-S (copolymer of1,3-butadi-,-

ene and styrene) tread stock compounded according to thefollowing-formula: Parts by Weight GR-S copolymer 100.00

Carbon black 45.00 Coal tar softener 5.00 Zinc oxide 5.00 Sulfur 2.00

The accelerators used werevthe carbon disulfide reaction productsprepared according to Examples 1 and 2. The amount of accelerator usedis indicated in the following table of properties. In the table theaccelerators are identified simply by their substituents. All stockswere cured 20, 40, 80 and 160 minutes'at 280 F., and listed under eachof the properties are the values obtainedon stocks cured for each ofthese several The modulus and tensile strength are recorded in poundsper'squ'are inch. and the @1011- gation in percentages.

' thione having the formula \CHL S in which R and R are from the groupof radicals consisting of alkyl, alkenyl, cycloalkyl and benzyl, each ofwhich contains no more than twenty carbon atoms.

2. A 3,6-dia1kyl- 1,3,6-thiadiazepine-2-thione having the formula inwhich R and R. are alkyl groups each containing one to twenty carbonatoms. 3. 3,6, dicyclohexyl 1,3,6 thladiazepine 2- thione.

4. 3,6-diisopropyl-1,3,6-thiadiazepine2-thione.

5. The process of producing an imidazolidine derivative which comprisesreacting equimolecular weights of carbon disulfide and a1,3-disubstituted imidazolidine, each substituent containing one totwenty carbon atoms and being of the class'of radicals consisting ofalkyl, alkenyl, cycloalkyl and benzyl, each containing no more thantwenty carbon atoms, and reacting within a temperature range whichincludes room temperature and the refluxing temperature of an 5 ethersolution thereof so as to prevent decomposition.

6. The process of reacting carbon disulfide and a 1,3-dialkylimidazolidine which comprises refluxing equimolecular weights of the twoin an inert solvent in which they are soluble, within a temperaturerange which includes room temperature and the refluxing temperature ofan ether solution thereof so as to prevent decomposition, each alkylsubstituent containing one to twenty carbon atoms.

'7. The process of reacting carbon disulfide and1,3-dicyclohexylimidazolidine which comprises refluxing equimolecularweights of the two in a solvent in which they are soluble, within atemperature range which includes room tempera ture and the refluxingtemperature of an ether solution thereof so as to prevent decomposition.

8. The process of reacting carbon disulfide and1,3-diisopropylimidazolidine which comprises refluxing equimolecularweights of the two in a solvent in which they are soluble, within atemperature range which includes room temperature and the refluxingtemperature of an ether solution thereof so as to prevent decomposition.

JAMES A. SHO-T'ION.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,170,059 Mathes Aug. 22, 19392,236,389 Williams Mar. 25, 1941

1. A 3,6-DISUBSTITUTED 1,3,6-THIADIAZEPHINE-2THIONE HAVING THE FORMULA